NASA Damage Map Aids California Wildfire Response

The
Advanced Rapid Imaging and Analysis (ARIA) team at NASA’s
Jet Propulsion
Laboratory and at Caltech, both in Pasadena,
California, created a damage proxy
map depicting areas in
Northern California that are likely damaged as a result
of the
region’s current outbreak of wildfires. The map has been
provided to
various agencies to aid in the wildfire response.

The
map is derived from synthetic aperture radar (SAR) images
taken before and
after this month’s northern California fires
by the Copernicus Sentinel-1
satellites, operated by ESA (the
European Space Agency). The “before”
image was taken on Sept.
27, 2017, and the later image on Oct. 9, 2017. Both
images
were taken at 7 p.m. PDT (10 p.m. EDT).

The damage proxy map covers the full area within the large red
polygon at the bottom
and measures 155 by 106 miles (250 by
170 kilometers). The inset figure at the top
shows a small
part of the map covering damage in the city of Santa Rosa,
indicated by red and yellow pixels. Each pixel measures about
98 feet (30
meters) across. The color variation from yellow to
red indicates increasingly
more significant ground surface
change. Preliminary validation was done by comparing
the map
to optical satellite imagery from DigitalGlobe. This damage
proxy map
should be used as guidance to identify damaged areas
and may be less reliable
over vegetated areas.

Sentinel-1
data were accessed through the Copernicus Open
Access Hub. The image contains
modified Copernicus Sentinel
data (2017), processed by ESA and analyzed by the
NASA-JPL/Caltech ARIA team. This research was carried out at
JPL under a
contract with NASA.